QCM : Cell Cycle and Chromosome Dynamics — 5 questions

Explication

Cytokinesis is the process of dividing the cytoplasm after nuclear division, leading to two distinct cells. Mitosis and meiosis refer to nuclear division, while karyokinesis is the division of the nucleus itself, which is part of mitosis or meiosis. The definition provided explicitly describes cytokinesis.

Explication

Nondisjunction is the failure of chromosomes to separate properly during cell division, which primarily causes aneuploidy, an abnormal number of chromosomes. Among the options, aneuploidy is directly caused by nondisjunction, making it the correct answer. Translocation and crossing over are different types of chromosome abnormalities that involve chromosome segments but are not caused by nondisjunction. Deletion involves loss of chromosome parts, not the failure of chromosome separation.

Explication

The source states that apoptosis is a regulated process that removes damaged or unnecessary cells without causing inflammation, whereas necrosis is uncontrolled and often results in inflammation. This fundamental difference makes option 0 the correct answer.

Explication

Paul M. Nurse is credited with discovering that cyclin-dependent kinases (Cdks) require binding to cyclins to become active and regulate the cell cycle, an essential breakthrough in understanding cell cycle control.

Explication

The centromere is the region where sister chromatids are joined, serving as the attachment point for spindle fibers during cell division. This is essential for proper segregation of chromosomes. The other options describe different chromosome features: a gene-coding sequence, a protein complex involved in chromatin structure, and chromosome telomeres, respectively.